Inspected 1st floor powder room toilet. Piston assembly came apart and gasket was not sealing. Reinstalled items and tested. Toilet is working as should at this time. If issue happens again, contacting American Standard for a replacement piston assembly will need to happen. Guide below states how to replace gasket. TURN OFF WATER SUPPLY & DRAIN TANK BY LIFTING CHAIN 1. DESCONNECT CHAIN HOOK FROM LEVER ARM 2. LIFT & SUPPORT THE FLOAT ASSEMBLY BY HOLDING THE GUIDE ROD WITH ONE HAND. 3. REMOVE UPPER FLOAT BY TURNING COUNTER-CLOCKWISE 4, REMOVE LOWER FLOAT LOCK RING BY TWISTING SLIGHTL COUNTER-CLOCKVISE & PULL DOWN TO REMOVE, 5. REMOVE SEAL FROM UPPER FLOAT REPLACE WITH NEW. 6 REPLACE LOWER LOCK RING BY ALIGNING SLOTS WITH TABS ON UPPER FLOAT, PRESS & TWIST CLOCKVWSE TO LOCK 7, RE-ATTACH FLOAT ASSEMBLY-TO GUIDE ROD BY TURNING CLOCKWISE UNTIL TIGHT, 8. RE-ATTACH HOOK TO LEVER ARM